1. Field of the Invention
The present invention relates to a protective cushion for a vehicle occupant""s head and, more particularly, to a cushion which can be inflated along windows of side doors in the event of a side impact or roll-over situation.
2. Description of Related Art
One such protective cushion for a vehicle occupant""s head is disclosed in International Patent Publication WO96/26087, particularly, FIG. 1 and FIG. 9 of the publication. The known cushion has a vacancy comprising a duct extending from the end at the front side of a vehicle (the front end) to the end at the rear side of the vehicle (the rear end) along the upper edge of the cushion. There are also a plurality of cells or chambers that extend downward from and communicate with the duct. Between the adjacent cells, an occupant-side sheet (hereinafter, sometimes referred to as xe2x80x9ccabin-side sheetxe2x80x9d) and a vehicle body-side sheet (hereinafter, sometimes referred to as xe2x80x9cdoor-side sheetxe2x80x9d) are joined.
According to the cushion disclosed in WO96/26087, the duct is formed by interweaving the cabin-side sheet and the door-side sheet. The duct thus formed is not ideal for introducing gas into the cells.
Accordingly, it is a general object of the invention to provide a protective cushion for a vehicle occupant""s head that alleviates or minimizes the above described difficulties.
It is an object of the present invention to provide a protective cushion for a vehicle occupant""s head that allows gas to be introduced into chambers, which are formed between sheets, in a timely manner.
It is yet another object of the present invention to provide a protective cushion for a vehicle occupant""s head that is simple and cost-effective to manufacture.
A preferred embodiment of the invention intended to accomplish at least some of the foregoing objects includes a protective cushion for a vehicle occupant""s head disposed in the vicinity of a corner between a ceiling and a side surface of a vehicle cabin and is adapted to be inflated with introduced gas downwardly along the side surface. The protective cushion includes an occupant-side sheet and a body-side sheet superposed on each other and sewn together so as to form a plurality of vacant chambers. Gas is introduced into the plurality of chambers which are positioned between the sheets and arranged in the longitudinal direction of a vehicle.
The cushion also has a longitudinally extended gas passage at its upper portion. The gas passage is constructed of a cylindrical member that is provided separate from the body-side and occupant-side sheets. There is at least one opening at an approximate midpoint of the gas passage that allows gas to be transferred from the cylindrical member to the plurality of chambers of the cushion.
In the protective cushion for a vehicle occupant""s head, gas supplied to the cylindrical member is supplied into plurality of chambers through an end of the cylindrical member and/or openings formed in the cylindrical member. By selecting the length of the cylindrical member and/or the positions of the openings, gas can be introduced into desired chambers from desired positions.
The cylindrical member may be made of a fabric sheet rolled to form a cylindrical member wall thickness which is at least as thick as twice the thickness of the cylindrical member sheet itself. When the cylindrical member sheet is rolled to form a wall with at least two layers, the layers may be affixed to one another by using an adhesive between the layers located in the vicinity of the openings formed in the cylindrical member. In the cases in which the cylindrical member is made from a sheet, the cylindrical member sheet, the cabin-side sheet, and the door-side sheet may be sewn together with a common thread or yarn. The sewing preferably is both for forming the cylindrical member and for sewing together the cabin-side sheet and the door-side sheet, thus reducing the man-hours required in manufacturing the cushion.
The cylindrical member sheet may have a pair of longer ends and a pair of shorter ends. In these instances, the longer ends are positioned between an end of the occupant-side sheet and an end of the body-side sheet.
The cushion may have a plurality of projections commonly extending from the cylindrical member, the occupant-side sheet, and the body-side sheet. The projections may have a plurality of holes through which bolts or rivets may be inserted to secure the cushion to the vehicle body. In this case, the force applied to the cylindrical member is transmitted directly to the vehicle body. In addition, if the cylindrical member is a sheet and if the cylindrical member sheet, the occupant-side sheet, and the body-side sheet are sewn together with a common thread or yard, the common thread or yarn may be positioned between the cylindrical member and the plurality of projections.
According to the present invention, the protective cushion may further comprise a closing element, including stitches or an adhesive, in the cylindrical member downstream portion from the opening in the gas flowing direction. This stitching closes or constricts the sectional area of the gas passage in the cylindrical member. Preferably, when the gas pressure in the cylindrical member reaches or exceeds a predetermined value, the sectional area of the gas passage is enlarged as a result of the stitching breaking. In this fashion, the closing element may serve to constrict the passage of the cylindrical member at least until termination of the inflation of the cushion.